We knew they could bite, scratch or make us sneeze, but Fido and Fluffy may be hazardous to our health for another reason: they can cause us to fall. America's dogs and cats, it turns out, can be blamed for injuries caused in an estimated 86,000 falls treated each year in the country's emergency rooms, federal health officials said today.

Nearly 88 percent of those injuries come at the paws of man's best friend, who's more apt to wound the fairer sex, epidemiologists report in today's Morbidity and Mortality Weekly Report (MMWR). About a quarter of those spills occur when a pet owner is walking his or her dog, and twice as many women as men are hurt.  

"Most people think of pets in terms of tripping over them. They don’t think of walking a dog as a hazard," Judy Stevens, an epidemiologist in the U.S. Centers for Disease Control and Prevention's (CDC) injury center, tells ScientificAmerican.com. Dogs, she adds, are more likely to be dangerous than cats because "they tend to be bigger and stronger and you have to walk them, which you don’t with cats." Women, she says, are more likely than men to take a tumble if a pup pulls during a stroll, because they generally weigh less and aren't as strong.

Stevens based the estimates on 7,456 pet-related falls treated in ERs that were collected between 2001 and 2006 by the government's National Electronic Injury Surveillance System All Injury Program. Fractures, contusions and abrasions were the most common types of wounds treated in those cases. Whereas children and 30- to 50-somethings were most often hurt, the most serious injuries were in people 75 and older, who more frequently suffered fractures that can be tougher for the elderly to recover from.

Most of the falls happened at or near home. Among the people hurt while walking their dog, a third of the injuries came from tripping over the pooch and a fifth from the canine pushing or pulling them. Nearly 9 percent of injuries occurred when someone toppled over their pet's toy or food bowl. Investigators weren’t able to sort out the circumstances of nearly 40 percent of doggie-related falls.

Scientific American features editor Christine Soares can attest to the dangers of dogs. Soares broke her left ankle in January while chasing her 10-month-old puppy, Murfee, around her dining room. After wearing a cast for seven weeks, Soares is now using a cane and is in physical therapy. "I faked right and went left and my foot didn’t go with me," she recalls.

But Soares doesn’t hold a grudge against Murfee, an 18-pound rescue mutt. "I can't blame the dog. I can only blame myself and the slippery floors," Soares says. "I was angry at myself for trying to keep pace with a 10-month-old puppy as a 44-year-old woman."

It's clear why pups might cause trouble—but cats? Nearly 12 percent of injuries from tumbles linked to kitties stemmed from incidents in which a person was chasing his or her feline friend – and ended up tripping over the elusive animal. But as with dogs, the circumstances of the cat-related falls were most of the time unclear.

Care to help us out? Message us about your injurious pet via Twitter or in the comment section below.

Image of Murfee, "worth a broken ankle," courtesy of Christine Soares